import React, { Component } from 'react'
// 引入store，用于获取redux中保存的状态
import store from '../../redux/store'

export default class Count extends Component {

  /*componentDidMount() {
    // 检测redux中状态的变化，只要变化，就调用render
    store.subscribe(() => {
      console.log('@')
      // this.render() xxx
      this.setState({})
    })
  }*/

  increment = () => {
    const {value} = this.selectNumber
  
    store.dispatch({type:'increment', data: value*1})
  
  }
  decrement = () => {
    const {value} = this.selectNumber
    store.dispatch({type:'decrement', data: value*1})
  }
  incrementIfOdd = () => {
    const {value} = this.selectNumber
    const count = store.getState()
    if(count % 2 !== 0) {
      store.dispatch({type:'increment', data: value*1})
    }
  }
  incrementAsync = () => {
    const {value} = this.selectNumber
    setTimeout(() => {
      store.dispatch({type:'increment', data: value*1})
    }, 1000)
  }

  render() {
    return (
      <div>
        <h1>当前求和为：{store.getState()}</h1>
        <select ref={c => this.selectNumber = c}>
          <option value="1">1</option>
          <option value="2">2</option>
          <option value="3">3</option>
        </select>&nbsp;&nbsp;
        <button onClick={this.increment}>+</button>&nbsp;&nbsp;
        <button onClick={this.decrement}>-</button>&nbsp;&nbsp;
        <button onClick={this.incrementIfOdd}>increment odd</button>&nbsp;&nbsp;
        <button onClick={this.incrementAsync}>increment async</button>
      </div>
    )
  }
}
